docs: def as_sql(self, qn, connection=None):
          """
          Create the proper SQL fragment. This inserts something like
          "(T0.flags & value) != 0".
  
          This will be called by Where.as_sql()
          """
          if self.bit:
              return ("(%s.%s | %d)" % (qn(self.table_alias), qn(self.column), self.bit.mask),
                      [])
          return ("(%s.%s & %d)" % (qn(self.table_alias), qn(self.column), self.bit.mask),
                  [])